Olfaction ImpactImpact of Nasoseptal Flap Harvest Technique on Olfaction Following Endoscopic Transsphenoidal Pituitary Surgery

Pituitary tumours have an estimated prevalence of 20% in the general population and the number of clinically relevant pituitary adenomas is increasing with time. When symptomatic, the standard of care required for pituitary adenomas is resection through an endoscopic transsphenoidal approach. There is however significant olfactory dysfunction following endoscopic transsphenoidal pituitary surgery with approximately 23% of patients reporting some degree of worsening in their sense of smell in the postoperative period.

Pedicled nasoseptal flaps are used to repair skull base defects following resection of skull base tumours. The superior incision is placed in close proximity to olfactory mucosa. Currently, these flaps are raised either with the use of electrocautery or scalpel. The use of electrocautery in surgery has provided surgeons with greater hemostasis when compared to a scalpel. This is of utmost importance in many regions of the head \& neck where highly vascularized tissue results in difficulties achieving adequate hemostasis and therefore limiting view of the surgical field. However, the use of electrocautery increases thermal damage to surrounding tissue and impairs wound healing when compared to a scalpel.

Although the transmission of thermal energy via electrocautery to adjacent mucosa containing olfactory epithelium may theoretically contribute to olfactory disturbances, no prospective randomized controlled trials have yet examined the impact of these two different techniques on postoperative olfactory function. The purpose of this research study is to determine the effects, if any, of electrocautery versus scalpel on olfaction in raising the nasoseptal flap for repairing skull base defects following transphenoidal surgery.